On Thursday, November 21, 2019 at 8:35:22 PM UTC-5, wrote:
The EPROM reader/programmer arrived yesterday and it works fine.
The UV EPROM eraser should be here in a day or two. Amazon apologized
for the delay. So I can copy the EPROMs just fine but I would really
like the ladder programs so that I can make some changes to the
machine.

I'm sure you know this but I've been bitten once and it may be worth mentioning.

I understand you're trying to back up your EPROM holding your program. We had a similar problem in a manufacturing plant, probably with an Allen Bradley PLC or similar. (it's been a while) The program went bad, we got the backup EPROM, and uploaded the saved program.

Except we didn't. The wording of upload and download was ambiguous and we accidentally saved the bad program from the machine onto the EPROM. We had one extra EPROM in the safe, got that out and €¦€¦€¦€¦ did exactly the same thing.

Everything was ladder logic and I came to hate those hardcopy printouts, but with enough time and patience we could type it back in. Ladder logic was theoretically understandable to the electricians but it violates every single concept in programming. Every line can refer to any other line - no modular programming, no single entry single exit, etc.